STONE-MASOX CATERPILLARS. 201 



been previously directed to their habits, we should have 

 considered them as portions of the wall ; for not one of 

 them was in motion, and it was only by the neat, turbi- 

 nated, conical form in which they had constructed their 

 habitations that we detected them. We tried the experi- 

 ment above-mentioned, of ejecting one of the caterpillars 

 from its tent, in order to watch its proceedings when 

 constructing another; but probably its haste to procure 

 shelter, or the artificial circumstances into which it was 

 thrown, influenced its operations, for it did not form so 

 good a tent as the first, the texture of the v/alls being much 

 slighter, while it was more rounded at the apex, and of course 

 not so elegant. Reaumur found, in all his similar experi- 

 ments, that the new structure equalled the old ; but most 

 of the trials of this kind which we have made correspond 

 with the inferiority which we have here recorded. The 

 process indeed is the same, but it seems to be done with 

 more hurry and less care. It may be, indeed, in some 

 cases, that the supply of silk necessary to unite the bits of 

 stone, earth, or lichen employed, is too scanty fur perfecting 

 a second structure. 



We remarked a very singular circumstance in the opera- 

 tions of our little architect, which seems to have escaped 

 the minute and accurate attention of Reaumur. When it 

 commenced its structure, it was indispensable to lay a 

 foundation for the walls about to be reared ; but as the 

 tent was to be moveable like the shell of a snail, and not 

 stationary, it would not have answered its end to cement 

 the foundation to the wall. We had foreseen this difficulty, 

 and felt not a little interested in discovering how it would 

 be got over. Accordingly, upon watching its movements 

 with some attention, we were soon gratified to perceive 

 that it used its own body as the primary support of the 

 building. It fixed a thread of silk upon one of its right 

 feet, warped it over to the corresponding left foot, and 

 upon the thread thus stretched between the two feet it 

 glued grains of stone and chips of lichen, till the wall was 

 of the required thickness. Upon this, as a foundation, it 

 continued to work till it had formed a small portion in 



